For suppressing developing explosions, e.g. of mill dusts, coal dusts and solvent vapors, one has hitherto used containers under continuous pressure and filled with extinguishing agent, preferably extinguishing powder, that, when needed, blow extinguishing agent into the space to be protected via a quick opening valve. For uniform distribution, in particular lateral spreading of the extinguishing agent, a corresponding nozzle is used that customarily has the form of a hemisphere that is slotted or provided with a plurality of bores (cf. company publication “HRD-Systeme,” June 1995, Total Walther Feuerschutz GmbH).
Further, fire extinguishing systems have became known that consist of tandem arrangement of a gas generator, an extinguishing agent container and an outlet opening. However, these devices are fundamentally unsuitable for suppressing a developing explosion. The reaction to an explosion must take place within the time range of a few milliseconds to effectively fight the explosion while it is arising, i.e. before the occurrence of the pressures typical of an explosion.
U.S. Pat. No. 870,479 describes an extinguishing agent cartridge wherein a central charge is triggered with the aid of freely laid fuses. Triggering is effected only by means of open fire; reaction to a developing explosion is fundamentally impossible. Powder atomization is suitable only for fighting fire.
According to U.S. Pat. No. 2,383,048, pyrotechnically generated pressure gas is introduced centrally into an extinguishing agent container with a relatively large cross section. Extinguishing agent and delivery gas are thus first mixed and then discharged together. This device, being a hand extinguisher, is equipped with only a small pyrotechnic charge, therefore also producing only a low discharge velocity and lateral distribution of extinguishing agent.
U.S. Pat. No. 5,305,957 proposes equipping an extinguisher with liquid extinguishing agent, a long, tubular acceleration path and a gas generator with low delivery pressure of about 10 bars. This obtains a high discharge velocity of extinguishing agent, but the lateral spread of the extinguishing agent jet remains low and the breakdown into droplets takes place only at a relatively large distance in front of the device due to the velocity-dependent air resistance. Thus, this extinguisher is suitable only for point-shaped fire-fighting.
Finally, DE 195 44 399 C2 from the applicant describes an assembly that is fundamentally suitable as an extinguisher for suppressing developing explosions. However, no indication is given of how to achieve an optimized extinguishing result using the known construction.
It is the problem of the present invention to state an extinguishing method suitable for suppressing developing dust explosions, for example of food dusts, in closed spaces within an extremely short time by means of a cloud of extinguishing agent dust filling the space volume.